Marisa Weiss, a Philadelphia oncologist and founder of Breastcancer.org, says the task force's conclusions were based on outdated assumptions about treatment and mammography. For example, studies show that digital mammography is more accurate among young women, but the USPSTF discussed only the standard film mammography. And it figured in certain harms that have been ameliorated over the years with procedures such as core biopsies rather than the more invasive open biopsies, as well as tests that can predict which women are likely to benefit from chemotherapy and which can skip it. She worries these recommendations will result in young women being entirely bypassed, so that women in their 50s will be diagnosed at later stages of cancer and will need more treatment.
All sides of the debate agree on several things: More research is necessary to more accurately capture an individual woman's risk of breast cancer and to ferret out the genetic or molecular characteristics of tumors that need more aggressive treatment and others that can be monitored for further changes. And most everyone acknowledges that mammography is imperfect and that women do not always have accurate information about what it can and cannot do. "We have oversimplified the message in a way that misrepresents the biology of the disease," says Barbara Brenner, executive director of Breast Cancer Action, a San Francisco-based advocacy group that has long questioned the emphasis on mammography. People with early breast cancer fall into three categories: a group of women with very aggressive disease that even routine mammography isn't likely to catch in time to prevent death, women with conditions like DCIS whose cancers may never become life-threatening, and a third group whose cancers are potentially dangerous and respond to current treatments, she says. The latter are the women helped by mammography, but it's not possible to know for sure who falls into that category.
The debate is over the women in whom to deploy an admittedly imperfect test until more is known about how to better predict who is most likely to reap its benefits, and over how that test should be used. Therese Bevers, medical director of the cancer prevention center and prevention outreach programs at M.D. Anderson Cancer Center in Houston, says that models might show that some low-risk populations more likely to develop less aggressive tumors could consider mammograms every two years. But a blanket recommendation to that effect is likely to miss aggressive tumors and pick up more of the slow-growing lesions, she says. Kerlikowske, however, says it makes sense to recommend against routine screening for women under 50, but that those with a close relative with breast cancer might instead start in their 40s with an every-other-year mammogram. Both acknowledge the test's flaws, but their starting points differ.
Lichtenfeld worries that the nuanced discussions about screening mammography may be lost in the shuffle. "The public needs to be informed and should be aware of the benefits and risks or harms of the test," he says. "The other side of the coin is that when the messages are confusing or conflicting or overly complex, the public will generally respond by saying, 'If they can't make up their minds, why should I do this test?' "
As for insurance reimbursement, since decisions are based on recommendations of many major groups (including the USPSTF and the ACS), this recommendation alone isn't likely to prevent women in their 40s from having mammograms covered by insurance. Petitti says the "C"-level recommendation given by the USPSTF is against routine mammography for women under 50, not against it in all cases.
Meantime, it's unclear whether women will follow the advice of the USPSTF or other bodies giving conflicting advice. "I think it points to a conversation with her doctor," Petitti says when asked about how women should take these recommendations. Weiss worries women are looking for a reason not to have an admittedly unpleasant test and that guidance such as this may give them the excuse to do so. The National Cancer Institute, for its part, says it will evaluate its own recommendations in light of today's report, including what women of above-average risk should do—a group the USPSTF did not address in detail. Stay tuned for more controversy.